丙泊酚对仔鼠海马磷酸化tau蛋白及β-淀粉样蛋白_(1-42)表达的影响

Effect of Propofol on Expression of Phosphorylated Tau Protein and Beta-amyloid_(1-42) Protein in Hippocampus of Offspring Rat

目的探讨怀孕大鼠注射丙泊酚对其后代空间认知探索能力及海马磷酸化tau蛋白(P-tau)、β-淀粉样蛋白(1-42)[Aβ(1-42)]沉积表达的影响。方法 3个月龄24只雌鼠与8只雄鼠按雌雄比3∶1合笼受孕。怀孕后按随机数字表法将孕鼠分为早期组(E组)、中期组(M组)、晚期组(L组)和对照组(C组),各6只。E组、M组、L组经腹腔注射丙泊酚80 mg·kg-1·d-1,连续注射7 d。C组注射同体积的0.9%氯化钠溶液代替丙泊酚。在孕鼠子代30日龄时进行Morris水迷宫实验,取其海马分别采用免疫组织化学和酶联免疫吸附实验,检测丝氨酸202位点磷酸化tau蛋白及Aβ(1-42)表达情况。结果与C组(65.60±7.23)s相比,E组(51.20±8.11)s、M组(36.00±6.44)s、L组(47.20±12.30)s,仔鼠空间学习记忆能力下降,均差异有统计学意义(P<0.05)。免疫组化检测显示M组仔鼠海马Aβ(1-42)和P-tau含量较E组、L组、C组高[Aβ(1-42):(27.38±5.90)比(12.65±2.08),(13.79±3.37),(65.60±7.23);P-tau:(26.35±5.83)比(13.65±3.46),(14.56±3.82),(8.49±1.20)]。酶联免疫吸附实验检测亦显示M组仔鼠海马Aβ(1-42)和P-tau含量较E组、L组、C组高[Aβ(1-42):(88.6±7.43)比(71.60±6.79),(13.79±3.37),(65.80±6.28);P-tau:(230.13±8.22)比(210.42±2.20),(210.95±1.75),(200.65±1.57)],均差异有统计学差异(P<0.05)。结论孕期多次注射丙泊酚损伤仔鼠空间学习记忆能力,孕中期暴露致损伤最为明显,其机制可能与海马P-tau、Aβ(1-42)沉积过度表达有关。

Objective To study the effects of propofol exposure during pregnancy on space cognitive and exploration abilities and expression of phosphorylated tau protein （ P-tau） and beta-amyloid protein[ Aβ（1-42） ] in hippocampus of the offspring. Methods Sprague-Dawley female （n=24） and male rats （n=8） of three months old were mated at the same cage at the ratio of 3：1. Pregnant rats were randomly divided into early group （group E）, medium group （group M）, late group （group L） and control group （ group C） , with 6 rats in each group. Groups E, M and L received propofol 80 mg · kg-1 · d-1 for 7 consecutive days. Propofol was replaced with equal volume of physiological saline in group C. Learning and memory of the 30-day offspring rats were assessed by using Morris water maze test. Then offspring rats were sacrificed to determine the expression of P-tau and Aβ（1-42） in the hippocampus by ELISA and immunohistochemistry. Results The learning and memory abilities were declined significantly in group E （51. 20±8. 11） s, group M （36. 00±6. 44） s and group L （47. 20±12. 30） s, as compared with group C （65. 60± 7. 23） s （all P〈0. 05）. The result of immunohistochemistry and ELISA showed that expression of Aβ（1-42） and P-tau in hippocampus was significantly higher in group M than in groups E, L and C[（immunohistochemistry： Aβ（1-42）, （27. 38±5. 90） vs. （12. 65± 2. 08）, （13. 79±3. 37）, and （65. 60±7. 23）; P-tau, （26. 35±5. 83） vs. （13. 65±3. 46）, （14. 56±3. 82）, and （8. 49±1. 20）;ELISA：Aβ（1-42） , （88. 6±7. 43） vs. （71. 60±6. 79）, （13. 79±3. 37）, and （65. 80±6. 28）;P-tau, （230. 13±8. 22） vs. （210. 42± 2.20）, （210.95±1. 75）, and （200. 65±1. 57）] （all P〈0.05）. Conclusion Multiple propofol injections may impair rat offspring’ s space cognitive abilities and exploration abilities, and the impairment is especially obvious in second trimester of pregnancy, which may be associated with over-expression of P-tau and Aβ（1-42） .